# US 9,433,373 B2 · Method and apparatus for mathematically characterizing ear canal geometry > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,433,373 B2 - Document ID: US9433373B2 - Status: Granted - Kind: B2 - Application number: 12/793,784 - Filed: 2010-06-04 - Published: 2010-12-09 - Granted: 2016-09-06 - Earliest claimed: 2009-06-05 - Assignees: Starkey Laboratories, Inc. - Applicants: Thomas Howard Burns - Inventors: Thomas Howard Burns - Web page: https://patentgrep.com/patent/US9433373B2 ## CPC - A61B 5/1076: {for measuring dimensions inside body cavities, e.g. using catheters (A61B3/1005 takes precedence)} - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract The present subject matter provides apparatus and methods for physically fitting a hearing assistance device, including mathematically characterizing a person's ear canal. The apparatus includes a housing adapted to be mechanically coupled to the person in proximity to the person's outer ear. An ultrasonic transducer array is located within at least a portion of the housing. The apparatus includes electronics within the housing, the electronics adapted to control the transducer array to alternate between transmitting and receiving ultrasonic energy. In various embodiments, a processor is adapted to characterize geometry of the ear canal using information from the ultrasonic transducer array obtained from scans of the ear canal. ## Claims ### Claim 1 An apparatus for mathematically modeling a person's ear canal, the apparatus comprising: a housing including an aperture; an ultrasonic transducer array located within at least a portion of the housing, the housing adapted to position the ultrasonic transducer array on a person's skull outside of and surrounding a pinna, such that at least a portion of the pinna is within the aperture; electronics within the housing, the electronics adapted to control the transducer array to transmit ultrasonic energy at a first frequency and receive ultrasonic energy at a second frequency, wherein the second frequency is different than the first frequency, wherein the transducer array is configured for a frequency operating range dependent on a measured depth of the ear canal, wherein the depth of the ear canal is measured at least in part using the ultrasonic transducer array; and a processor within the housing, the processor configured to control each transducer in the transducer array and adapted to mathematically characterize geometry of the ear canal using information from the ultrasonic transducer array obtained from scans of the ear canal, wherein the mathematically characterized geometry of the ear canal is generated to create specifications for producing a hearing aid shell customized for at least a portion of the ear canal. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the processor includes a digital signal processor (DSP). ### Claim 3 (depends on 1) The apparatus of claim 1, wherein the electronics are adapted to operate transducers in the transducer array in pulse-echo mode. ### Claim 4 (depends on 1) The apparatus of claim 1, wherein the transducer array is adapted to operate in a range of frequencies from 1 MHz to 18 MHz. ### Claim 5 (depends on 1) The apparatus of claim 1, wherein the transducer array is adapted to operate in a range of frequencies from 3 MHz to 12 MHz. ### Claim 6 (depends on 1) The apparatus of claim 1, wherein the transducer array includes multiple piezoceramic transducers. ### Claim 7 (depends on 1) The apparatus of claim 1, wherein the transducer array includes multiple piezocrystal transducers. ### Claim 8 (depends on 1) The apparatus of claim 1, wherein the transducer array includes transducers fabricated from piezopolymer cylinders operating with 1-3 connectivity. ### Claim 9 (depends on 1) The apparatus of claim 1, wherein the transducer array includes transducers fabricated from a piezopolymer matrix operating with 2-2 connectivity. ### Claim 10 (depends on 1) The apparatus of claim 1, wherein at least one surface of the housing has a circular shape. ### Claim 11 (depends on 1) The apparatus of claim 1, wherein at least one surface of the housing has an oval shape. ### Claim 12 (depends on 1) The apparatus of claim 1, wherein at least one surface of the housing has a square shape. ### Claim 13 (depends on 1) The apparatus of claim 1, wherein at least one surface of the housing has a rectangular shape. ### Claim 14 (depends on 1) The apparatus of claim 1, wherein at least one surface of the housing has a rounded rectangular shape. ### Claim 15 A method for mathematically modeling a person's ear canal, the method comprising: positioning an ultrasonic transducer system on a person's skull outside of and surrounding a pinna, wherein the ultrasonic transducer system includes an ultrasonic transducer array within a housing having an aperture, and wherein the positioning includes placing the housing such that at least a portion of the pinna is within the aperture; scanning the ear canal using the ultrasonic transducer system, including transmitting ultrasonic energy at a first frequency and receiving ultrasonic energy at a second frequency, wherein the second frequency is different than the first frequency, wherein the transducer array is configured for a frequency operating range dependent on a measured depth of the ear canal, wherein the depth of the ear canal is measured at least in part using the ultrasonic transducer array; and using a processor within the housing and configured to control each transducer in the transducer array to process information from the ultrasonic transducer system to obtain a representation of geometry of the ear canal, wherein the representation of geometry of the ear canal is generated to create specifications for producing a hearing aid shell customized for at least a portion of the ear canal. ### Claim 16 (depends on 15) The method of claim 15, wherein scanning the ear canal includes using transducers in pulse-echo mode. ### Claim 17 (depends on 15) The method of claim 15, further comprising: sending the representation of the geometry of the ear canal to a hearing instrument manufacturer. ### Claim 18 (depends on 17) The method of claim 17, wherein sending the representation includes sending data using internet. ### Claim 19 (depends on 17) The method of claim 17, further comprising: manufacturing a hearing instrument shell utilizing the representation of the geometry of the ear canal in a digital shell making procedure. ### Claim 20 (depends on 19) The method of claim 19, wherein the digital shell making procedure includes stereo lithography.